A number of child-safety devices are known in the art to protect children and others (e.g., mentally handicapped) from unauthorized access to cabinets, cupboards, and the like.
One such product is marketed under the name SAFETY1ST TOT LOK FOR CABINETS AND DOORS and is illustrated on www.drugstore.com and www.safety1st.com websites. The TOT LOK uses magnetically activated latch that is attached to the inside of a door. Applying a magnetic “key” to the other side of the door releases the latch.
A number of Patents are related to the TOT LOK device. Richards, U.S. Pat. No. 4,919,464, issued Apr. 23, 1990, and incorporated herein by reference, discloses a magnetically operated latch. This latch is located on the INSIDE of the cabinet and requires some drilling to install. A magnetic “knob” is placed on the outside of the cabinet to unlatch the latch, but it does not appear that this knob is used to actually pull open the cabinet door. Richards explicitly states that a conventional handle (not shown) is used to open the door (Col. 2, lines 65-68) although the magnetic knob may remain attached to the door. This type of device would probably tend to scar the finish of the cabinet by sliding the knob against the outside. In addition, it requires some extensive machining to the cabinet to install the rod and latch hardware.
Note that the rod installation is particularly troublesome, as it requires the user to drill a substantially sized hole, partially through the cabinet door. Careless drilling could result in the user putting a hole through the cabinet face, ruining the cabinet. From casual inspection of the TOT LOK latches at the local LOWES™ home improvement center, it appears that the rod portion may have been deleted from the final design. Nevertheless, the TOT LOK requires that holes be drilled into the inside of the cabinet door to install. Moreover, the TOT LOK apparatus is not cheap.
Richards, U.S. Pat. No. 4,969,273, issued Nov. 13, 1990, and incorporated herein by reference, discloses a method of marking a cabinet or door for drilling using a sticker template. This Patent is not really relevant to the present invention, but illustrates the amount of careful machining necessary in order to install the TOT LOK magnetic catch on a door. The template is really needed, as accurate drilling may be necessary in order to insure the magnetic catch is properly installed.
Richards, U.S. Pat. No. 5,076,623, issued Dec. 31, 1991, and incorporated herein by reference, is a Continuation-In-Part of the Richards '464 Patent and appears to disclose minor variations on the original TOT LOK design.
Maccaferri, U.S. Pat. No. 5,188,405, issued Feb. 23, 1993, and incorporated herein by reference appears to disclose the identical TOT LOK invention as Richards '464 filed nearly a year earlier. However, the two applications do not claim priority from one another and although the drawings are identical in every aspect, it is clear they were drawn by different draftsmen. Maccaferri appears to be claiming only an improvement in the Richards design, namely a locking means to hold the latch open when it is not desired to lock the cabinet.
The TOT LOK Patents teach a device which uses a magnet to release a CATCH, not to open the door. Moreover, Richards explicitly states that his device cannot open the door, but the user must rely upon the existing handle. The TOT LOK device is not easy to install, as it requires drilling into the cabinet as illustrated by Richards drilling template Patent. In addition, the catch release of Maccaferri defeats the whole point of TOT LOK. A user must manually test each cabinet to insure that the latch is not defeated. Yet, the catch release of Maccaferri is necessary, as it would be cumbersome for a user to have to release a catch every time they wanted to use a cabinet.
While TOT LOK represents an effort in improving the safety of cabinetry, its cost, complexity, difficult installation, modification of cabinetry, and lack of easy use, leave it lacking. For example, a parent renting a home would be hesitant to use TOT LOK as it would modify or alter the cabinetry, and the landlord might not approve of such alterations. In addition, the installation requires a number of hand tools as well as a drill, and thus takes considerable time and skill to install. What is needed is a simple device which can be installed by any parent or consumer, even those without hand tools skills.
Other Patents are known in the art, which show various types of child safety devices. JULIAN, U.S. Pat. No. 6,431,616, issued Aug. 13, 2002, and incorporated herein by reference, discloses a child safety latch assembly. This complex apparatus requires that the user hold the drawer face while pulling the knob in order to release the drawer. It is not clear why merely pulling the knob will not release the drawer. The device is complex and requires a fairly complicated installation procedure. Moreover, this apparatus does not appear to be safety oriented, but rather provides only a positive latching mechanism to prevent a drawer from opening accidentally. While Julian mentions that child safety is one motivation behind his latch, it is unclear to applicant how this device provides any child safety. To hold one hand on the drawer face while pulling the knob may be intuitive to a child. Thus, there is no positive mechanism that prevents a child from opening such a drawer or cupboard.
CHRONES, U.S. Pat. No. 4,082,351, issued Apr. 4, 1978, and incorporated herein by reference, discloses a safety cover for a doorknob. This safety cover is typical of the various sliding covers sold at safety stores and on-line to parents. While useful for doorknobs, they are not applicable to cabinets and the like. Since the device rotates over the doorknob, it may prevent a child from opening a door. When the child tries to turn the cover, it rotates freely, and the doorknob does not turn. However, if this device were applied to a cupboard or drawer knob, it would provide no safety. If the child pulled on the cover, the cupboard or drawer would open.
HOLLANDER, U.S. Pat. No. 4,253,690, issued Mar. 3, 1981, and incorporated herein by reference, discloses a safety knob using a ratchet mechanism. Again, this knob does not appear to be readily adaptable to kitchen cabinets with friction or magnetic catches, as it is designed for rotating door knobs. The ratchet mechanism prevents a child from rotating the doorknob in one direction. The device does not prevent anyone from pulling on the knob, however.
The idea of providing removable knobs for child safety appears to be known in the art. DUEFRENE, U.S. Pat. No. 2,440,170, issued Apr. 20, 1948, and incorporated herein by reference, discloses a removable knob, which he teaches may be used for furniture and the like. The knob snaps off by using an interference fit between two pliable materials. DUEFRENE explicitly discloses that his removable knob may be used as a child-safety device (Col. 1, lines 50-55), but does not disclose any magnetic feature.
One problem with DUEFRENE is that his knob snaps onto a screw or base. Thus, even when the knob is removed, the base or screw is still present and can be used to pull open a cabinet. See, for example, FIGS. 4, 5, 6, and 10 of DUEFRENE. In order to be really effective as a child safety knob, a removable knob should leave no base or screw that a child could grasp and open the cabinet with. In addition, the mechanical snap fastener of DUEFRENE would appear to wear over time, and thus the apparatus could lose its effectiveness (grip) after repeated use.
The idea of magnetically removable knobs or handles is known in other arts, but it does not appear that any of these types of knobs or handles have been applied to the child safety problem. The TOK LOK described above uses magnets, but only to release a catch.
ENDOU, Published Japanese Patent Application Ser. No. JP 4-10151074A, published Jun. 9, 1998, and incorporated herein by reference, discloses a magnetic knob, which may be applied to pot lids. By removing the knob, the lids may be nested for better storage. Note that his “magnet board” 3 (See FIG. 2) is attached to the pot lid by a flange. It appears that this knob is designed to be built-in to the pot lid at the factory, and is not an add-on device for installation by a consumer. ENDOU does not teach or suggest applying his magnetic knob to other applications.
ADINOLFI, U.S. Pat. No. 5,159,739, issued Nov. 3, 1992, and incorporated herein by reference, discloses a sanitary equipment handler using magnetically held, detachable handle. ADINOLFI discloses that a surgeon or the like can hold the handle to open drawers or move equipment without having to touch the equipment with his hands.
ADINOLFI uses magnetic plates mounted on the devices to be moved (drawers, lights, etc.) and provides a knob-like sterilize-able handle (FIG. 1) made of a ferrous material to attach to such magnetic plates. The ADINOLFI design requires a number of expensive magnets, one for each cabinet door or drawer. ADINOLFI probably uses the magnets on the drawers, as constantly autoclaving magnets on handles (to sterilize them) would probably demagnetize them. For an application like surgical devices, such an expense is probably acceptable. But for a consumer application, providing a number of expensive and powerful magnets would not be cost-effective.
In addition, the device of ADINOLFI requires that these magnets be installed to each device to be manipulated by the sterilized handle. The devices to be manipulated must have the magnets built-in to them or have them attached using hardware attached through holes 8. Thus, drilling or machining of the device to be manipulated is required, which necessitates the alteration of the device to be manipulated, as well as the use of power tools to install the device.
There are other disadvantages of ADINOLFI as well. The presence of so many magnets could create problems, as watches, jewelry, forks, knives, and other cutlery, could attach themselves to the magnets of ADINOLFI if it could be adapted for kitchen use (Note that ADINOLFI makes no such teaching or suggestion). As ADINOLFI is directed toward surgical applications, this may not be a problem in that environment, as many if not most surgical tools are made from stainless steels, which are non-magnetic. However, in households, magnetic materials abound. Watches in particular can be damaged by large magnets. The large magnetic plates are also unsightly and would be difficult to mount, as drilling and screwing would be required.
BLANCHET, U.S. Pat. No. 3,302,566, issued Feb. 7, 1967, and incorporated herein by reference, discloses a magnetic handle for a series of rubber stamps. BLANCHET uses two magnets having their poles in opposite relationship (N-S) so as to attract to one another. One magnet is mounted to the stamp handle, and the other to the rubber stamp body. BLANCHET probably used this two-magnet technique as it allowed him to use less powerful magnets. Note that the size of the handle shaft precludes the use of a magnet of any appreciable size. The use of two magnets increases the overall cost of the design. BLANCHET does not teach or suggest the use of his invention outside of the rubber stamp art.
Thus, a requirement remains in the art for an inexpensive, easy to install, and easy to use system that can provide “child-proofing” of cabinets without having to drill holes in the cabinets. Such a system should have an easy visual way of determining whether the cabinets are secured without having to manually latch each cabinet. Moreover, such a system should be easy enough for the average homeowner to install without the use of screws, drills, or even tools.